title: Endoscopic features of colorectal serrated lesions using image-enhanced endoscopy with pathological analysis.
abstract: OBJECTIVE
  To clarify of the features of sessile serrated adenoma/polyp (SSA/P) observed with image-enhanced endoscopy using immunohistochemical staining.
  
  
  METHODS
  Twenty-five hyperplastic polyps (HP) and 46 SSA/P were studied with autofluorescence imaging (AFI) and magnifying endoscopy with narrow-band imaging (ME-NBI). AFI color change, capillary dilatation, existence of a mucous layer on the tumor surface, and pit dilatation under ME-NBI were examined retrospectively. Immunohistochemical staining was performed with the proliferation-associated antigen MIB-1 (Ki-67).
  
  
  RESULTS
  Using AFI, a magenta color was observed in 32% of HP and 44% of SSA/P. With NBI observation, capillary dilatation was observed in 4% of HP and 11% of SSA/P, a mucous cap was observed in 60% of HP and 94% of SSA/P, and pit dilatation was observed in 28% of HP and 80% of SSA/P. When magenta color, capillary dilatation, mucous cap, and pit dilatation were used for the differential diagnosis of SSA/P from HP, the sensitivity, specificity, and accuracy were 43, 68, and 52% for AFI, respectively, 10, 96, and, 41% for capillary dilatation, respectively, 94, 40, and 75% for mucous cap, respectively, and 80, 72, and 78% for pit dilatation, respectively. Compared with HP, MIB-1-positive cells were more frequently distributed in the gland's intermediate zone in SSA/P.
  
  
  CONCLUSIONS
  The biological malignant potential of SSA/P could be higher compared with HP as suggested by the MIB-1 stain. Therefore, endoscopic differentiation of SSA/P from HP is important, and the findings of a mucous cap and dilatated pit might be helpful for the differentiation of SSA/P from HP.
authors.affiliation: Department of Internal Medicine, Division of Gastroenterology and Hepatology, The Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nakao
authors.forename: Shoichi
authors.initials: S
authors.lastname: Saito
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Ohya
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Aihara
authors.forename: Seiji
authors.initials: S
authors.lastname: Arihiro
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kato
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ikegami
authors.forename: Hisao
authors.initials: H
authors.lastname: Tajiri
mesh_terms: D000328:Adult; D000368:Aged; D049109:Cell Proliferation; D016009:Chi-Square Distribution; D003111:Colonic Polyps / Q000737:chemistry / Q000473:pathology*; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006965:Hyperplasia; D007089:Image Enhancement; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D062048:Narrow Band Imaging; D061848:Optical Imaging; D011237:Predictive Value of Tests; D012189:Retrospective Studies
chemical_list: D019394:Ki-67 Antigen